Crystal modifications of elobixibat

ABSTRACT

The present invention relates to crystal modifications of N-{(2R)-2-[({[3,3-dibutyl-7-(methyl-thio)-1,1-dioxido-5-phenyl-2,3,4,5-tetrahydro-1,5-benzothiazepin-8-yl]oxy}acetyl)amino]-2-phenylethanolyl}glycine (elobixibat), more specifically crystal modifications I, IV, MeOH-1, EtOH-1, 1-PrOH-1 and 2-PrOH-1. The invention also relates to a process for the preparation of these crystal modifications and to a pharmaceutical composition comprising crystal modification IV.

The present invention relates to crystal modifications ofN-{(2R)-2-[({[3,3-dibutyl-7-(methyl-thio)-1,1-dioxido-5-phenyl-2,3,4,5-tetrahydro-1,5-benzothiazepin-8-yl]oxy}acetyl)amino]-2-phenylethanolyl}glycine(elobixibat), more specifically crystal modifications I, IV, MeOH-1,EtOH-1, 1-PrOH-1 and 2-PrOH-1. The invention also relates to a processfor the preparation of these crystal modifications and to apharmaceutical composition comprising crystal modification IV.

BACKGROUND

WO 02/50051 discloses the compound1,1-dioxo-3,3-dibutyl-5-phenyl-7-methylthio-8-(N-{(R)-1′-phenyl-1′-[N′-(carboxymethyl)carbamoyl]methyl}carbamoylmethoxy)-2,3,4,5-tetrahydro-1,5-benzothiazepine(elobixibat; IUPAC name:N-{(2R)-2-[({[3,3-dibutyl-7-(methylthio)-1,1-dioxido-5-phenyl-2,3,4,5-tetrahydro-1,5-benzothiazepin-8-yl]oxy}acetyl)amino]-2-phenyl-ethanolyl}glycine).This compound is an ileal bile acid transporter (IBAT) inhibitor, whichcan be used in the treatment or prevention of diseases such asdyslipidemia, constipation, diabetes and liver diseases. According tothe experimental section of WO 02/50051, the last synthetic step in thepreparation of elobixibat consists of the hydrolysis of a tert-butoxylester under acidic conditions. The crude compound was obtained byevaporation of the reaction mixture under reduced pressure andpurification of the residue by preparative HPLC usingacetonitrile/ammonium acetate buffer (50:50) as eluent (Example 43).After freeze drying the product, no crystalline material was identified.

It would be desirable to discover a form of elobixibat that issufficiently robust to be suitable for formulation as a pharmaceutical.

During crystallization studies that form the basis for this invention,it was observed using X-ray powder diffraction (XRPD) techniques thatelobixibat crystallized from many solvents or mixtures of solvents byincorporating solvent molecules in its structure, thereby formingspecific solvates or mixed solvates. Thus, different crystalmodifications of elobixibat were obtained in many solvents orcombinations of solvents. Different crystal modifications were evenobtained when the same solvent was used. Further, using thermalgravimetric analysis (TGA), it was concluded that different samples ofthe same crystal modification may contain different amounts of solvents.Additional crystal modifications of elobixibat were obtained when theincorporated organic solvent molecules were evaporated from thecrystallized solvates. Thus, the experimental work supporting thepresent application found that many crystal modifications of elobixibatwere unstable, and/or were observed to transform into other crystalmodifications. It was therefore difficult to obtain consistent resultsby repeating similar experiments.

Different solvated crystal modifications may be revealed by using a veryfast X-ray detector and withdrawing a wet sample from a slurry of thesolid material to be analyzed onto a sample holder, keeping the sampleat the experiment temperature and then analysing the sample quickly andrepeatedly as it dries. This technique can show an initially formedsolvate or mixed solvate, the desolvated modification or a mixture ofthe two. If more than one partially or completely desolvated crystalmodification exists, there are even more possible variations ofXRPD-data. It was thus a further challenge just to obtain XRPD-data fora pure crystal modification.

Various crystal modifications may have disadvantages including avariable degree of crystallinity and difficulties in handling andformulating. Thus, there is a need for stable crystal modifications ofelobixibat having improved properties with respect to stability, bulkhandling and solubility. It is therefore an object of the presentinvention to provide a stable and highly crystalline crystalmodification of elobixibat.

SUMMARY OF THE INVENTION

The invention provides various crystal modifications of elobixibat. Inone aspect, the crystal modification is a monohydrate of elobixibat. Amonohydrate includes 0.9-1.1 moles of water associated with a crystalper mole of elobixibat. The amount of water calculated herein excludeswater adsorbed to the surface of the crystal. In certain embodiments,the monohydrate is stable for at least one year, such as at least 17months.

In another aspect, which may be related to the first aspect, theinvention provides a crystalline monohydrate of elobixibat, where thecrystalline form is prepared by forming an elobixibat monoalcoholate,substantially converting the monoalcoholate to an ansolvate and exposingthe ansolvate to water vapor. The monoalcoholate can be a methanolate,an ethanolate, a 1-propanolate, a 2-propanolate or a mixture of thesealcohols. In certain embodiments, the monohydrate cannot be formedwithout forming a monoalcoholate as an intermediate.

The invention also includes other crystal modifications includingcrystal modification I and crystal modification IV, along withintermediates used to prepare these crystal modifications.

The invention further provides methods of treating a condition describedherein and use of the crystal modifications described herein in treatinga condition described herein and in the manufacture of a medicament forthe treatment of a condition described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the X-ray powder diffractogram of crystal modification IV.

FIG. 2 shows the X-ray powder diffractogram of crystal modificationEtOH-1.

FIG. 3 shows a comparison between the X-ray powder diffractograms forcrystal modifications EtOH-1 (solid line, bottom) and IV (dotted line,top).

FIG. 4 shows the X-ray powder diffractogram of crystal modification I.

FIG. 5 shows the X-ray powder diffractogram of crystal modification IVbefore (bottom) and after TGA analysis (top).

FIG. 6 shows the X-ray powder diffractogram of crystal modification IVobtained (from the bottom) from methanol, ethanol, 1-propanol and2-propanol.

FIG. 7 shows the X-ray powder diffractogram of crystal modifications(from the bottom) MeOH-1, EtOH-1, 1-PrOH-1 and 2-PrOH-1 obtained frommethanol, ethanol, 1-propanol and 2-propanol.

FIG. 8 shows the X-ray powder diffractogram of crystal modificationMeOH-1.

FIG. 9 shows the X-ray powder diffractogram of crystal modification1-PrOH-1.

FIG. 10 shows the X-ray powder diffractogram of crystal modification2-PrOH-1.

FIG. 11 shows the DVS mass change plot for crystal modification IV. Thetwo curves show the % RH change (right y-axis) and the sample responsein weight % (left y-axis). The pre-drying step is shown on the far leftof the diagram.

FIGS. 12A and 12B show a plot of water uptake as a function of % RH forcrystal modification IV. The sample used in FIG. 12A was obtained frommaterial produced on lab scale, and the sample used in FIG. 12B wasobtained from GMP material produced on pilot plant scale.

FIG. 13 shows the DVS mass change plot for crystal modification I. Thetwo curves show the % RH change (right y-axis) and the sample responsein weight % (left y-axis). The pre-drying step is shown on the far leftof the diagram.

FIG. 14 shows a plot of water uptake as a function of % RH for crystalmodification I.

FIG. 15 shows a micrograph of crystal modification IV, taken betweenslightly uncrossed polarizers and using a 10 times objective.

FIG. 16 shows a micrograph of crystal modification I, taken betweenslightly uncrossed polarizers and using a 10 times objective.

FIG. 17 shows the high-resolution X-ray powder diffractograms of crystalmodification I and crystal modification IV.

FIG. 18 shows the high-resolution X-ray powder diffractograms of crystalmodification I, tablets comprising crystal modification I and placebotablets.

FIG. 19 shows the high-resolution X-ray powder diffractograms of crystalmodification I, tablets comprising crystal modification I after 8-weekstorage under 40° C., 75% relative humidity and placebo tablets.

FIG. 20 shows the high-resolution X-ray powder diffractograms of crystalmodification IV, tablets comprising crystal modification IV and placebotablets.

FIG. 21 shows the high-resolution X-ray powder diffractograms of crystalmodification IV, tablets comprising crystal modification IV after 8-weekstorage under 40° C., 75% relative humidity and placebo tablets.

DETAILED DESCRIPTION OF THE INVENTION

In a first aspect, the invention relates to crystal modification IV ofelobixibat. It has surprisingly been found that this very stable crystalmodification of elobixibat can be obtained, starting from what wasinitially thought to be the most stable dried form, crystal modificationI. Crystal modification I was used as the drug substance in Phase I andII clinical trials. When this crystal modification I is slurried inethanol or a mixture of ethanol and water at a temperature between about0 and 70° C., such as between about 0 and 25° C., another crystalmodification is gradually obtained, namely the ethanol solvate EtOH-1.This solvate has been confirmed to be a monoethanolate. Upon drying thissolvate, such as under reduced pressure and elevated temperature, EtOH-1loses its solvate molecules and turns into a partly crystallineansolvate. When the ansolvate is subsequently exposed to moisture fromthe air, it readily absorbs one equivalent of water. During these twophase transformations, the crystal structure is more or less preserved.The resulting monohydrate, hereinafter referred to as crystalmodification IV, was found to be stable for at least up to 17 months ofstorage, such as under ambient, open conditions. This crystalmodification furthermore has better thermodynamic stability and ahigher, more consistent degree of crystallinity than crystalmodification I and other, less crystalline forms of elobixibat.

It was thereafter discovered that elobixibat behaves similarly in otheralcohols, such as methanol, 1-propanol and 2-propanol, or a 50:50 volumemixture of alcohol and water at room temperature. Under theseconditions, the solvates MeOH-1, 1-PrOH-1 and 2-PrOH-1, which aresubstantially isostructural with EtOH-1, may be obtained from a slurry.The alcohol solvates thus formed behave similarly to EtOH-1, in thatthey form an intermediate as they begin to lose their solvate moleculesand then, when the alcohol has been substantially evaporated off, absorbwater and transform to modification IV. FIG. 6 shows X-ray powderdiffraction data for modification IV, obtained from different alcohols.

The isolation of this stable crystal modification IV was notstraightforward. Although crystal modification IV is a monohydrate, itcannot be obtained directly from crude elobixibat or crystalmodification I, because when these are stirred in a mixture of water andalcohol, the alcohol solvate (MeOH-1, EtOH-1, 1-PrOH-1 or 2-PrOH-1) isformed instead. The alcohol solvate is believed to be thethermodynamically more stable crystal modification under theseconditions. Interestingly, the alcohol solvate does not spontaneouslytransform into crystal modification IV either—not even when exposed to100% relative humidity—if the alcohol molecules are not first removed,for example by drying, from the crystal structure of the solvate.

In one embodiment, the invention relates to crystal modification IVhaving an X-ray powder diffraction (XRPD) pattern, obtained withCuKα1-radiation, with at least specific peaks at °2θ positions 6.3±0.2and/or 19.4±0.2.

In another embodiment, the invention relates to crystal modification IVhaving an XRPD pattern, obtained with CuKα1-radiation, with specificpeaks at ° 2θ positions 6.3±0.2 and 19.4±0.2 and one or more of thecharacteristic peaks: 10.2±0.2, 10.5±0.2, 9.4±0.2, 9.5±0.2, 12.5±0.2,14.6±0.2, 15.6±0.2, and 23.3±0.2.

In another embodiment, the invention relates to crystal modification IVhaving an XRPD pattern, obtained with CuKα1-radiation, with specificpeaks at ° 2θ positions 6.3±0.2, 19.4±0.2, 10.2±0.2, 10.5±0.2, 9.4±0.2,and 9.5±0.2.

In another embodiment, the invention relates to crystal modification IVhaving an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions 6.3±0.2, 19.4±0.2, 10.2±0.2,10.5±0.2, 9.4±0.2, 9.5±0.2, 12.5±0.2, 14.6±0.2, 15.6±0.2, 23.3±0.2, andone or more of 8.3±0.2, 11.3±0.2, 13.4±0.2, 13.9±0.2, 16.3±0.2,16.6±0.2, 18.2±0.2, 18.8±0.2, 19.1±0.2, 19.3±0.2, 19.7±0.2, 19.8±0.2,20.5±0.2, 21.0±0.2, 21.3±0.2, 21.4±0.2, 22.6±0.2, 22.9±0.2, 23.1±0.2,23.9±0.2, 24.5±0.2, 24.7±0.2, 25.0±0.2, 25.2±0.2, 25.4±0.2, 25.7±0.2,26.7±0.2, 26.9±0.2, 28.3±0.2, and 28.9±0.2.

According to one embodiment the invention relates to crystalmodification IV having an XRPD pattern, obtained with CuKα1-radiation,with characteristic peaks at ° 2θ positions: 6.3±0.2, 8.3±0.2, 9.4±0.2,9.5±0.2, 10.2±0.2, 10.5±0.2, 11.3±0.2, 12.5±0.2, 13.4±0.2, 13.9±0.2,14.6±0.2, 15.6±0.2, 16.3±0.2, 16.6±0.2, 18.2±0.2, 18.8±0.2, 19.1±0.2,19.3±0.2, 19.4±0.2, 19.7±0.2, 19.8±0.2, 20.5±0.2, 21.0±0.2, 21.3±0.2,21.4±0.2, 22.6±0.2, 22.9±0.2, 23.1±0.2, 23.3±0.2, 23.9±0.2, 24.5±0.2,24.7±0.2, 25.0±0.2, 25.2±0.2, 25.4±0.2, 25.7±0.2, 26.7±0.2, 26.9±0.2,28.3±0.2, and 28.9±0.2.

In yet another embodiment, the invention relates to crystal modificationIV having an XRPD pattern, obtained with CuKα1-radiation, substantiallyas shown in FIG. 1.

In a second aspect, the invention relates to crystal modification EtOH-1of elobixibat.

In one embodiment, the invention relates to crystal modification EtOH-1having an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions 6.1±0.2 and 18.9±0.2 or havingcharacteristic peaks at ° 2θ positions 6.1±0.2 and 18.9±0.2 and one ormore of the characteristic peaks: 10.1±0.2, 14.5±0.2, 18.4±0.2,19.1±0.2, 20.7±0.2, 10.4±0.2, 13.1±0.2, and 11.1±0.2.

In another embodiment, the invention relates to crystal modificationEtOH-1 having an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions: 6.1±0.2, 18.9±0.2, 10.1±0.2,14.5±0.2, 18.4±0.2, 19.1±0.2, 20.7±0.2, 10.4±0.2, 13.1±0.2, 11.1±0.2 andone or more of 8.0±0.2, 9.3±0.2, 12.2±0.2, 13.7±0.2, 15.1±0.2, 15.3±0.2,15.9±0.2, 17.2±0.2, 17.8±0.2, 20.3±0.2, 21.2±0.2, 22.0±0.2, 22.2±0.2,22.5±0.2, 23.6±0.2, 24.0±0.2, 24.5±0.2, 24.7±0.2, 25.2±0.2, and26.3±0.2.

In another embodiment, the invention relates to crystal modificationEtOH-1 having an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions: 6.1±0.2, 8.0±0.2, 9.3±0.2,10.1±0.2, 10.4±0.2, 11.1±0.2, 12.2±0.2, 13.1±0.2, 13.7±0.2, 14.5±0.2,15.1±0.2, 15.3±0.2, 15.9±0.2, 17.2±0.2, 17.8±0.2, 18.4±0.2, 18.9±0.2,19.1±0.2, 20.3±0.2, 20.7±0.2, 21.2±0.2, 22.0±0.2, 22.2±0.2, 22.5±0.2,23.6±0.2, 24.0±0.2, 24.5±0.2, 24.7±0.2, 25.2±0.2, and 26.3±0.2.

In yet another embodiment, the invention relates to crystal modificationEtOH-1 having an XRPD pattern, obtained with CuKα1-radiation,substantially as shown in FIG. 2.

In a third aspect, the invention relates to crystal modification MeOH-1of elobixibat.

In one embodiment, the invention relates to crystal modification MeOH-1having an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions 6.2±0.2 and 18.9±0.2 or havingcharacteristic peaks at ° 2θ positions 6.2±0.2 and 18.9±0.2 and one ormore of the characteristic peaks: 10.1±0.2, 14.6±0.2, 18.6±0.2,19.1±0.2, 22.2±0.2, 24.7±0.2, 12.3±0.2, 13.3±0.2, and 16.1±0.2.

In another embodiment, the invention relates to crystal modificationMeOH-1 having an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions: 6.2±0.2, 18.9±0.2, 10.1±0.2,14.6±0.2, 18.6±0.2, 19.1±0.2, 22.2±0.2, 24.7±0.2, 12.3±0.2, 13.3±0.2,16.1±0.2 and one or more of 8.1±0.2, 9.3±0.2, 10.5±0.2, 10.9±0.2,13.0±0.2, 14.4±0.2, 15.8±0.2, 17.6±0.2, 20.3±0.2, 20.7±0.2, 21.0±0.2,22.7±0.2, 24.0±0.2, 24.3±0.2 and 26.1±0.2.

In another embodiment, the invention relates to crystal modificationMeOH-1 having an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions: 6.2±0.2, 8.1±0.2, 9.3±0.2,10.1±0.2, 10.5±0.2, 10.9±0.2, 12.3±0.2, 13.0±0.2, 13.3±0.2, 14.4±0.2,14.6±0.2, 15.8±0.2, 16.1±0.2, 17.6±0.2, 18.6±0.2, 18.9±0.2, 19.1±0.2,20.3±0.2, 20.7±0.2, 21.0±0.2, 22.2±0.2, 22.7±0.2, 24.0±0.2, 24.3±0.2,24.7±0.2, and 26.1±0.2.

In yet another embodiment, the invention relates to crystal modificationMeOH-1 having an XRPD pattern, obtained with CuKα1-radiation,substantially as shown in FIG. 8.

In a fourth aspect, the invention relates to crystal modification1-PrOH-1 of elobixibat.

In one embodiment, the invention relates to crystal modification1-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions 6.1±0.2 and 19.0±0.2 or havingcharacteristic peaks at ° 2θ positions 6.1±0.2 and 19.0±0.2 and one ormore of the characteristic peaks: 10.0±0.2, 14.4±0.2, 18.3±0.2,18.8±0.2, 20.5±0.2, 10.3±0.2, 13.0±0.2, and 11.0±0.2.

In another embodiment, the invention relates to crystal modification1-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions: 6.1±0.2, 19.0±0.2, 10.0±0.2,14.4±0.2, 18.3±0.2, 18.8±0.2, 20.5±0.2, 10.3±0.2, 13.0±0.2, 11.0±0.2 andone or more of 7.9±0.2, 9.2±0.2, 12.1±0.2, 13.6±0.2, 15.0±0.2, 15.3±0.2,15.8±0.2, 17.1±0.2, 17.6±0.2, 20.2±0.2, 21.1±0.2, 21.9±0.2, 22.1±0.2,22.4±0.2, 23.5±0.2, 23.8±0.2, 24.3±0.2, 24.5±0.2, 25.4±0.2, and26.2±0.2.

In another embodiment, the invention relates to crystal modification1-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions: 6.1±0.2, 7.9±0.2, 9.2±0.2,10.0±0.2, 10.3±0.2, 11.0±0.2, 12.1±0.2, 13.0±0.2, 13.6±0.2, 14.4±0.2,15.0±0.2, 15.3±0.2, 15.8±0.2, 17.1±0.2, 17.6±0.2, 18.3±0.2, 18.5±0.2,18.8±0.2, 19.0±0.2, 19.4±0.2, 20.2±0.2, 20.5±0.2, 21.1±0.2, 21.9±0.2,22.1±0.2, 22.4±0.2, 23.1±0.2, 23.5±0.2, 23.8±0.2, 24.3±0.2, 24.5±0.2,25.4±0.2, 26.0±0.2 and 26.2±0.2.

In yet another embodiment, the invention relates to crystal modification1-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation,substantially as shown in FIG. 9.

In a fifth aspect, the invention relates to crystal modification2-PrOH-1 of elobixibat.

In one embodiment, the invention relates to crystal modification2-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions 6.1±0.2 and 19.0±0.2 or havingcharacteristic peaks at ° 2θ positions 6.1±0.2 and 19.0±0.2 and one ormore of the characteristic peaks: 10.0±0.2, 14.4±0.2, 18.3±0.2,18.8±0.2, 20.5±0.2, 10.3±0.2, 12.9±0.2, and 11.0±0.2.

In another embodiment, the invention relates to crystal modification2-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions: 6.1±0.2, 19.0±0.2, 10.0±0.2,14.4±0.2, 18.3±0.2, 18.8±0.2, 20.5±0.2, 10.3±0.2, 12.9±0.2, 11.0±0.2 andone or more of 9.1±0.2, 12.1±0.2, 13.6±0.2, 14.9±0.2, 15.2±0.2,15.7±0.2, 17.1±0.2, 17.6±0.2, 18.5±0.2, 19.4±0.2, 20.2±0.2, 21.1±0.2,21.7±0.2, 22.1±0.2, 22.3±0.2, 23.1±0.2, 23.4±0.2, 23.7±0.2, 24.1±0.2,24.4±0.2, 24.6±0.2, 25.1±0.2, 25.4±0.2, 25.9±0.2, 26.2±0.2, 27.4±0.2 and29.2±0.2.

In another embodiment, the invention relates to crystal modification2-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions: 6.1±0.2, 9.1±0.2, 10.0±0.2,10.3±0.2, 11.0±0.2, 12.1±0.2, 12.9±0.2, 13.6±0.2, 14.4±0.2, 14.9±0.2,15.2±0.2, 15.7±0.2, 17.1±0.2, 17.6±0.2, 18.2±0.2, 18.5±0.2, 18.9±0.2,19.0±0.2, 19.4±0.2, 20.2±0.2, 20.5±0.2, 21.1±0.2, 21.7±0.2, 22.1±0.2,22.3±0.2, 23.1±0.2, 23.4±0.2, 23.7±0.2, 24.1±0.2, 24.4±0.2, 24.6±0.2,25.0±0.2, 25.4±0.2, 25.9±0.2, 26.2±0.2, 27.4±0.2 and 29.2±0.2.

In yet another embodiment, the invention relates to crystal modification2-PrOH-1 having an XRPD pattern, obtained with CuKα1-radiation,substantially as shown in FIG. 10.

In a sixth aspect, the invention relates to crystal modification I ofelobixibat.

In one embodiment, the invention relates to crystal modification Ihaving an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions 5.2±0.2 and/or 10.0±0.2.

In another embodiment, the invention relates to crystal modification Ihaving an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions: 5.2±0.2 and 10.0±0.2 and one ormore of the characteristic peaks: 4.9±0.2, 6.0±0.2, 7.6±0.2, 10.5±0.2,11.3±0.2, 18.8±0.2, 20.4±0.2, and 22.9±0.2.

In another embodiment, the invention relates to crystal modification Ihaving an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions: 5.2±0.2, 10.0±0.2, 4.9±0.2,6.0±0.2, 7.6±0.2, 10.5±0.2 and 11.3±0.2.

In another embodiment, the invention relates to crystal modification Ihaving an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions: 5.2±0.2, 10.0±0.2, 4.9±0.2,6.0±0.2, 7.6±0.2, 10.5±0.2, 11.3±0.2, 18.8±0.2, 20.4±0.2, 22.9±0.2, andone or more of 3.1±0.2, 4.4±0.2, 7.4±0.2, 7.8±0.2, 8.2±0.2, 12.4±0.2,13.3±0.2, 13.5±0.2, 14.6±0.2, 14.9±0.2, 16.0±0.2, 16.6±0.2, 16.9±0.2,17.2±0.2, 17.7±0.2, 18.0±0.2, 18.3±0.2, 19.2±0.2, 19.4±0.2, 20.1±0.2,20.7±0.2, 20.9±0.2, 21.1±0.2, 21.4±0.2, 21.8±0.2, 22.0±0.2, 22.3±0.2,23.4±0.2, 24.0±0.2, 24.5±0.2, 24.8±0.2, 26.4±0.2, 27.1±0.2 and 27.8±0.2.

In another embodiment, the invention relates to crystal modification Ihaving an XRPD pattern, obtained with CuKα1-radiation, withcharacteristic peaks at ° 2θ positions: 3.1±0.2, 4.4±0.2, 4.9±0.2,5.2±0.2, 6.0±0.2, 7.4±0.2, 7.6±0.2, 7.8±0.2, 8.2±0.2, 10.0±0.2,10.5±0.2, 11.3±0.2, 12.4±0.2, 13.3±0.2, 13.5±0.2, 14.6±0.2, 14.9±0.2,16.0±0.2, 16.6±0.2, 16.9±0.2, 17.2±0.2, 17.7±0.2, 18.0±0.2, 18.3±0.2,18.8±0.2, 19.2±0.2, 19.4±0.2, 20.1±0.2, 20.4±0.2, 20.7±0.2, 20.9±0.2,21.1±0.2, 21.4±0.2, 21.8±0.2, 22.0±0.2, 22.3±0.2, 22.9±0.2, 23.4±0.2,24.0±0.2, 24.5±0.2, 24.8±0.2, 26.4±0.2, 27.1±0.2 and 27.8±0.2.

In yet another embodiment, the invention relates to crystal modificationI having an XRPD pattern, obtained with CuKα1-radiation, substantiallyas shown in FIG. 4.

An advantage with crystal modification IV is that it is morethermodynamically stable at normal conditions (21° C., 10-30% relativehumidity) than crystal modification I and other crystal modifications ofelobixibat obtained from methanol, ethanol, 1-propanol or 2-propanol, orfrom mixtures of any of these alcohols and water. This allows for astable and secure manufacturing process of the drug substance and drugformulation.

Certain forms of elobixibat, such as crystal modification I ofelobixibat, contain a non-stoichiometric amount of water. In such forms,the amount of water may vary (e.g., dependent on the relative humidityof the air, or between different batches). In contrast, crystalmodification IV is a stoichiometric monohydrate, i.e. it contains aboutone mole of water per mole of substance (typically from 0.9-1.1 moles ofwater per mole of substance, not including water adsorbed to the surfaceof a crystal). This gives crystal modification IV a more stable weightat varying relative humidity.

Crystal modification IV is a highly crystalline monohydrate, which canbe produced by a controlled transformation process via the ethanolsolvate EtOH-1 or via the isostructural alcohol solvates MeOH-1,1-PrOH-1 and 2-PrOH-1. The crystal structure of EtOH-1 remains similarwhen the ethanol is evaporated and replaced by water. Further, therelatively stable degree of crystallinity of crystal modification IVresults in a reproducible solubility of the compound. This is of specialimportance for compounds that are to be used in pharmaceuticalpreparations, where each tablet or capsule containing the activepharmaceutical ingredient should have the same pharmacologicalproperties. Thus, crystal modification IV is more favourable forpreparing pharmaceutical formulations of elobixibat than other crystalmodifications of elobixibat discovered to date.

Yet another advantage with crystal modification IV is that the crystalhabit is more three dimensional compared to the crystal modification I,which is more two dimensional (needle shaped). This gives crystalmodification IV advantageous properties with regard to bulk handling andformulation. For instance, there is reduced or even no need to sieve thematerial, for example to break such crystals, and it can more easily bemixed with excipients during formulation.

In another aspect, the invention relates to a process for thepreparation of crystal modification IV. This process involves thepreparation and isolation of crystal modification EtOH-1, or one of theisostructural alcohol solvates MeOH-1, 1-PrOH-1 and 2-PrOH-1, fromeither crude or pure elobixibat. In one embodiment, the processcomprises the steps of:

-   a) preparing a saturated solution of elobixibat in alcohol or a    mixture of alcohol and water in a vessel;-   b) adding an excess of elobixibat to the saturated solution of    step a) so as to obtain a slurry;-   c) maintaining stirring of the slurry, optionally at about 5 to 25°    C., preferably 20 to 25° C. for a period of several hours up to    several days or even a week or more;-   d) recovering the solid obtained in step c), followed by drying the    solid in vacuum until removal of substantially all alcohol; and-   e) exposing the dry solid obtained in step d) to moisture from the    air.

The crude or pure starting material in step a) is amorphous elobixibator another crystal modification of elobixibat. In certain embodiments,elobixibat is essentially free from solvents other than water. In apreferred embodiment, the starting material is crystal modification I,which is a relatively stable crystal modification of elobixibat. Crystalmodification I can be obtained from crude, amorphous elobixibat, asdescribed in the experimental section. Its X-ray powder diffractogram isshowed in FIG. 4.

In certain embodiments, the saturated solution of elobixibat used instep a) is free from any solvents except methanol, ethanol, 1-propanol,2-propanol and water, such as less than 0.5% w/w solvents exceptmethanol, ethanol, 1-propanol, 2-propanol and water. If a mixture ofmethanol and water, ethanol and water, 1-propanol and water or2-propanol and water is used, the amount of methanol, ethanol,1-propanol or 2-propanol should be at least 5% w/w in certainembodiments. Most preferably, the solvent is at least 90% or even 100%w/w methanol, ethanol, 1-propanol or 2-propanol.

The solid obtained in step c) is crystal modification MeOH-1, EtOH-1,1-PrOH-1 or 2-PrOH-1. It is believed that in methanol, ethanol,1-propanol or 2-propanol, or in a mixture of methanol, ethanol,1-propanol or 2-propanol and water, crystal modification MeOH-1, EtOH-1,1-PrOH-1 or 2-PrOH-1 is the most thermodynamically stable form. Thus,when the suspension of step b) is stirred at about 5 to 25° C., such as20-25° C. (preferably for methanol), for a longer period of time, atsuch temperature, MeOH-1, EtOH-1, 1-PrOH-1 or 2-PrOH-1 will crystallize.

Crystal modification MeOH-1 is a methanol solvate, crystal modificationEtOH-1 is an ethanol solvate, crystal modification 1-PrOH-1 is a1-propanol solvate and crystal modification 2-PrOH-1 is a 2-propanolsolvate. When these solvates are dried under reduced pressure andelevated temperature, they lose their alcohol molecules and turn into anansolvate. In order to obtain a full transformation from the alcoholsolvate form to the monohydrate form, MeOH-1, EtOH-1, 1-PrOH-1 or2-PrOH-1 must be dried, so as to substantially remove the alcoholembedded in the crystals. Preferably, the solid is dried under vacuum atelevated temperatures, such as about 50° C., or such as about 65° C.

When the ansolvate crystals are exposed to moisture from the air, watermolecules are absorbed and a monohydrate is formed, crystal modificationIV. Absorption of water takes place at relative humidity as low as 10%.For reproducible results and high degree of crystallinity, it ispreferred that the anhydrate crystals are exposed to air at a relativehumidity of 20-60% at 25° C. By means of thermal gravimetric analysis,differential scanning calorimetry, Karl Fischer titration and DynamicVapor Sorption analysis, it has been shown that crystal modification IVis a monohydrate.

Alternatively, crystal modification IV can be prepared by adding seedcrystals to a saturated solution of elobixibat in methanol, ethanol,1-propanol or 2-propanol or a mixture of methanol, ethanol, 1-propanolor 2-propanol and water. Thus, in another embodiment, the processcomprises the steps of:

-   a) preparing an supersaturated solution of elobixibat in alcohol or    a mixture of alcohol and water, in a vessel;-   b) adding seed crystals to the supersaturated solution of step a);-   c) maintaining stirring until a solid is obtained;-   d) recovering the solid obtained in step c), followed by drying the    solid in vacuum until removal of the alcohol; and-   e) exposing the dry solid obtained in step d) to moisture from the    air.

The crude or pure starting material in step a) is amorphous elobixibator another crystal modification of elobixibat which in certainembodiments is free from solvents other than alcohol and water.

In certain embodiments, the supersaturated solution of elobixibat usedin step a) is free from any solvents except alcohol and water, such asless than 0.5% solvents except alcohol and water. If a mixture ofalcohol and water is used, the amount of alcohol should be at least 5%w/w in certain embodiments. Preferably, the solvent is methanol,ethanol, 1-propanol or 2-propanol.

The supersaturated solution can be prepared by dissolving startingmaterial in warm methanol, ethanol, 1-propanol or 2-propanol or a warmmixture of methanol, ethanol, 1-propanol or 2-propanol and water, andthen cooling the resulting solution. The warm solvent preferably has aninitial temperature of about 40 to 45° C., and the solution is thencooled to a temperature such as about 25° C.

The seed crystals should be of crystal modification IV. The addition ofseed crystals will accelerate the formation and crystallization ofMeOH-1, EtOH-1, 1-PrOH-1 or 2-PrOH-1. The stirring time in step c) cantherefore be considerably shorter, such as 15 hours, or such as 10hours. The stirring can be maintained at a lower temperature, such as 5to 10° C., or such as 0 to 5° C.

Interestingly, even though crystal modification IV is a monohydrate, itcannot be obtained directly from crystal modification I when stirred ina mixture of water and methanol, ethanol, 1-propanol or 2-propanol. Insuch a mixture, crystal modification I transforms into the alcoholsolvate MeOH-1, EtOH-1, 1-PrOH-1 or 2-PrOH-1, respectively, all of whichare believed to be a thermodynamically more stable crystal modificationthan crystal modification I under these conditions. Surprisingly, whenthe formed MeOH-1, EtOH-1, 1-PrOH-1 or 2-PrOH-1 subsequently is exposedto 100% relative humidity, it still does not transform into themonohydrate. This shows that the alcohol molecules must be substantiallyremoved from the crystal structure before water molecules can enter andchange the structure to crystal modification IV.

When crystal modification IV is stirred in methanol, ethanol, 1-propanolor 2-propanol, or in a mixture of methanol, ethanol, 1-propanol or2-propanol and water, it transforms again into MeOH-1, EtOH-1, 1-PrOH-1or 2-PrOH-1. It is speculated that this transformation occurs withinonly a few minutes. This is likely a result of the high degree ofsimilarity between the XRPD patterns for crystal modifications MeOH-1,EtOH-1, 1-PrOH-1, 2-PrOH-1 and IV (see FIG. 3 and FIG. 7). Since thepatterns are so similar, it is believed, albeit without reliance on suchtheory, that the transformation may occur without dissolution andsubsequent re-crystallization, but rather by a rearrangement in thesolid state.

Elobixibat is an ileal bile acid transporter (IBAT) inhibitor. The ilealbile acid transporter (IBAT) is the main mechanism for re-absorption ofbile acids from the GI tract. Partial or full blockade of that IBATmechanism will result in lower concentration of bile acids in the smallbowel wall, portal vein, liver parenchyma, intrahepatic biliary tree,and extrahepatic biliary tree, including the gall bladder. Diseaseswhich may benefit from partial or full blockade of the IBAT mechanismmay be those having, as a primary pathophysiological defect, symptoms ofexcessive concentration of bile acids in serum and in the above organs.

Thus, in another aspect, the invention also relates to crystalmodification IV of elobixibat for use in therapy.

Crystal modification IV is useful in the prophylaxis or treatment ofhypercholesterolemia, dyslipidemia, metabolic syndrome, obesity,disorders of fatty acid metabolism, glucose utilization disorders,disorders in which insulin resistance is involved, type 1 and type 2diabetes mellitus, liver diseases, diarrhoea during therapy comprisingan IBAT inhibitor compound, constipation including chronic constipation,e.g. functional constipation, including chronic constipation andconstipation predominant irritable bowel syndrome (IBS-C). Treatment andprophylaxis of constipation is described in WO 2004/089350.

Further potential diseases to be treated with the crystal modificationIV are selected from the group consisting of liver parenchyma, inheritedmetabolic disorders of the liver, Byler syndrome, primary defects ofbile acid (BA) synthesis such as cerebrotendinous xanthomatosis,secondary defects such as Zellweger's syndrome, neonatal hepatitis,cystic fibrosis (manifestations in the liver), ALGS (Alagillessyndrome), progressive familial intrahepatic cholestasis (PFIC),autoimmune hepatitis, primary biliary cirrhosis (PBC), liver fibrosis,non-alcoholic fatty liver disease, NAFLD/NASH, portal hypertension,general cholestasis such as in jaundice due to drugs or duringpregnancy, intra- and extrahepatic cholestasis such as hereditary formsof cholestasis such as PFIC1, primary sclerosing cholangitis (PSC), gallstones and choledocholithiasis, malignancy causing obstruction of thebiliary tree, symptoms (scratching, pruritus) due tocholestasis/jaundice, pancreatitis, chronic autoimmune liver diseaseleading to progressive cholestasis, pruritus of cholestatic liverdisease and disease states associated with hyperlipidaemic conditions.

Other diseases to be treated with the crystal modification IV areselected from the group consisting of hepatic disorders and conditionsrelated thereto, fatty liver, hepatic steatosis, non-alcoholicsteatohepatitis (NASH), alcoholic hepatitis, acute fatty liver, fattyliver of pregnancy, drug-induced hepatitis, iron overload disorders,hepatic fibrosis, hepatic cirrhosis, hepatoma, viral hepatitis andproblems in relation to tumours and neoplasmas of the liver, of thebiliary tract and of the pancreas.

Thus, in one embodiment, the invention relates to crystal modificationIV of elobixibat for use in the treatment and/or prophylaxis of adisease or disorder as listed above.

In another embodiment, the invention relates to the use of crystalmodification IV of elobixibat in the manufacture of a medicament for thetreatment and/or prophylaxis of a disease or disorder as listed above.

In yet another embodiment, the invention relates to a method oftreatment and/or prophylaxis of a disease or disorder as listed above ina warm-blooded animal, comprising administering an affective amount ofcrystal modification IV of elobixibat to a warm-blooded animal in needof such treatment and/or prophylaxis.

Another aspect of the invention relates to a pharmaceutical compositioncomprising an effective amount of crystal modification IV, inassociation with a pharmaceutically acceptable diluent or carrier.

Yet another aspect of the invention relates to the use of crystalmodification IV in the preparation of a pharmaceutical composition,comprising admixing crystal modification IV with a pharmaceuticallyacceptable diluent or carrier.

The pharmaceutical composition may further comprise at least one otheractive substance, such as an active substance selected from an IBATinhibitor; an enteroendocrine peptide or enhancer thereof; a dipeptidylpeptidase-IV inhibitor; a biguanidine; an incretin mimetic; athiazolidinone; a PPAR agonist; a HMG Co-A reductase inhibitor; a bileacid binder; a TGR5 receptor modulator; a member of the prostone classof compounds; a guanylate cyclase C agonist; a 5-HT4 serotonin agonist;or a pharmaceutically acceptable salt of any one these activesubstances. Examples of such combinations are also described inWO2012/064268.

Crystal modification IV will normally be administered to a warm-bloodedanimal at a unit dose within the range of 5 to 5000 mg per square meterbody area, i.e. approximately 0.1 to 100 mg/kg or 0.01 to 50 mg/kg, andthis normally provides a therapeutically-effective dose. A unit doseform, such as a tablet or capsule, will usually contain about 1 to 250mg of active ingredient, such as about 1 to 100 mg, or about 5 to 50 mg,e.g. about 1 to 20 mg. The daily dose can be administered as a singledose or divided into one, two, three or more unit doses. An orallyadministered daily dose of an IBAT inhibitor is preferably within 0.1 to1000 mg, more preferably 1 to 100 mg, such as 5 to 15 mg.

The dosage required for the therapeutic or prophylactic treatment willdepend on the route of administration, the severity of the disease, theage and weight of the patient and other factors normally considered bythe attending physician when determining the individual regimen anddosage levels appropriate for a particular patient.

DEFINITIONS

The term “crystal modification” refers to a crystalline solid phase ofan organic compound. A crystal modification can be either a solvate oran ansolvate.

The term “solvate” refers to a crystalline solid phase of an organiccompound, which has solvent molecules incorporated into its crystalstructure. A “hydrate” is a solvate wherein the solvent is water,whereas a “mixed solvate” is a solvate containing molecules from morethan one solvent.

The term “slurry” refers to a saturated solution to which an overshootof solid is added, thereby forming a mixture of solid and saturatedsolution, a “slurry”.

As used herein, the terms “treatment,” “treat,” and “treating” refer toreversing, alleviating, delaying the onset of, or inhibiting theprogress of a disease or disorder, or one or more symptoms thereof, asdescribed herein. In some embodiments, treatment may be administeredafter one or more symptoms have developed. In other embodiments,treatment may be administered in the absence of symptoms. For example,treatment may be administered to a susceptible individual prior to theonset of symptoms (e.g., in light of a history of symptoms and/or inlight of genetic or other susceptibility factors). Treatment may also becontinued after symptoms have resolved, for example to prevent or delaytheir recurrence.

When reference is made herein to a crystalline compound, preferably thecrystallinity as estimated by X-ray powder diffraction data is greaterthan about 70%, such as greater than about 80%, particularly greaterthan about 90%, more particularly greater than about 95%. In embodimentsof the invention, the degree of crystallinity as estimated by X-raypowder diffraction data is greater than about 98%, preferably greaterthan about 99%, wherein the % crystallinity refers to the percentage byweight of the total sample mass which is crystalline.

Preferably a crystal modification according to the invention issubstantially free from other crystal modifications of the compound.Preferably, the described crystal modifications of elobixibat includesless than, for example, 20%, 15%, 10%, 5%, 3%, or particularly, lessthan 1% by weight of other crystal modifications of elobixibat. Thus,preferably, the purity of the described crystal modifications ofelobixibat is >80%, >85%, >90%, >95%, >97%, or particularly >99%.

The invention will now be described by the following examples which donot limit the invention in any respect. All cited documents andreferences are incorporated by reference.

ABBREVIATIONS

cr. mod. crystal modificationEtOH ethanolh hour(s)HDPE high density polyethyleneLDPE low density polyethyleneMeOH methanolmin. minute(s)1-PrOH 1-propanol2-PrOH 2-propanol

EXPERIMENTAL METHODS X-Ray Powder Diffraction (XRPD) Analysis

Dry samples were lightly ground in an agate mortar, if needed, and werethen smeared out on a sample holder. Slurry samples were added to thesample holder as wet and were analyzed both wet and dry. XRPD data werecollected on a cut Silicon Zero Background Holder (ZBH) or on a PorousAlumina Filter Sample Holder, using a PANalytical X'Pert Prodiffractometer, equipped with an X'celerator or a PIXcel detector. Thesample was spun during analysis and Cu-radiation was used. The followingexperimental settings were used:

Tube tension and current: 40 kV, 50 mAWavelength alpha1 (CuKα1): 1.5406 ÅWavelength alpha2 (CuKα2): 1.5444 ÅWavelength alpha1 and alpha2 mean (CuKα): 1.5418 ÅStart angle [2 theta]: 1-4°End angle [2 theta]: 30-40°Analysis time: 50 s (“1 min scan”), 125 s (“2 min scan”), 192 s (“3 minscan”), 397 s (“6 min scan”), 780 s (“13 min scan”), 1020 s (“17 minscan”), 4560 s (“1 h scan”)

Unless indicated otherwise, when calculating the peak positions from theXRPD-data, the data was first stripped from the contribution from CuKα2and was then corrected against an internal standard (Al₂O₃).

It is known in the art that an X-ray powder diffraction pattern may beobtained having one or more measurement errors depending on measurementconditions (such as equipment, sample preparation or machine used). Inparticular, it is generally known that intensities in an XRPD patternmay fluctuate depending on measurement conditions and samplepreparation.

For example, persons skilled in the art of XRPD will realise that therelative intensities of peaks may vary according to the orientation ofthe sample under the test and on the type and setting of the instrumentused. The skilled person will also realise that the position ofreflections can be affected by the precise height at which the samplesits in the diffractometer and the zero calibration of thediffractometer. The surface planarity of the sample may also have asmall effect. Hence a person skilled in the art will appreciate that thediffraction pattern presented herein is not to be construed as absoluteand any crystalline form that provides a powder diffraction patternsubstantially identical to those disclosed herein fall within the scopeof the present disclosure (for further information, see R. Jenkins andR. L. Snyder, “Introduction to X-ray powder diffractometry”, John Wiley& Sons, 1996).

Thermogravimetric Analysis (TGA)

Approximately 1-5 mg of sample was added to a tared Platinum cup whichwas then placed in the weighting position of a Perkin-Elmer Pyris 1 TGAanalyzer. The furnace was raised and the starting weight of the samplewas recorded. The heating program was then started. The sample washeated at a rate of 10° C./min, starting at 25° C. and ending at 90-300°C., depending on where a constant temperature could be attained. Thesample was purged with dry nitrogen gas during analysis.

Dynamic Vapor Sorption (DVS)

Approximately 15-20 mg of the sample was weighed into a quartzreceptacle, which was then released of static electricity by exposing itto a radioactive source. The quartz receptacle was then positioned in aSurface Measurements System Ltd DVS Advantage instrument. The sample wasdried with dry nitrogen gas until a dm/dt below 0.002% per minute wasreached. The instrument was running in dm/dt-mode using a dm/dt windowof 5 minutes, a minimum stage time of 10 minutes and a maximum stagetime of 360 minutes. The sample was then subjected to two consecutivesorption-desorption cycles, using d/m/dt-mode parameters above, and eachcycle running from 0-95-0% relative humidity (% RH). One cycle consistedof 20 steps, those between 0-90% RH were taken in 10% RH each.

Differential Scanning Calorimetry (DSC)

Approximately 2 mg of a sample was weighed into an aluminium DSC pansealed non-hermetically with an aluminium lid (sealed pan). The samplewas then loaded into a Perkin-Elmer Diamond DSC cooled and held at 30°C. Once a sufficiently stable heat-flow response was obtained, thesample was heated to 150° C. at a scan rate of 5° C./min and theresulting heat flow response monitored. A nitrogen purge was used toprevent thermally induced oxidation of the sample during heating andalso to reduce the thermal lag through the sample to increase theinstrument sensitivity. Prior to analysis, the instrument wastemperature and heat-flow calibrated using an indium reference standard.

For cryo-DSC experiments, the Perkin-Elmer Diamond DSC was cooled andheld at 5° C., and the sample was then analysed from 5 to 200° C. at ascan rate of 10° C./minute.

The starting material1,1-dioxo-3,3-dibutyl-5-phenyl-7-methylthio-8-(N-{(R)-1′-phenyl-1′-[N′-(t-butoxycarbonylmethyl)carbamoyl]methyl}carbamoylmethoxy)-2,3,4,5-tetrahydro-1,5-benzothiazepinecan be prepared as described in WO02/50051.

EXAMPLES Example 1 Preparation of Crystal Modification I

Toluene (11.78 L) was charged to a 20 L round-bottom flask with stirringand1,1-dioxo-3,3-dibutyl-5-phenyl-7-methylthio-8-(N-{(R)-1′-phenyl-1′-[N′-(t-butoxycarbonylmethyl)carbamoyl]-methyl}carbamoylmethoxy)-2,3,4,5-tetrahydro-1,5-benzothiazepine(2.94 kg) was added. Formic acid (4.42 L) was added to the reaction massat 25-30° C. The temperature was raised to 115-120° C. and stirred for 6hours. The reaction was monitored by HPLC to assure that not more than1% of the starting material remained in the reaction mass. The reactionmass was cooled to 40-43° C. Purified water (11.78 L) was added whilestirring. The reaction mass was further cooled to 25-30° C. and stirredfor 15 min.

The layers were separated and the organic layer was filtered through acelite bed (0.5 kg in 3 L of toluene) and the filtrate was collected.The celite bed was washed with toluene (5.9 L), the filtrates werecombined and concentrated at 38-40° C. under vacuum. The reaction masswas then cooled to 25-30° C. to obtain a solid.

Ethanol (3.7 L) was charged to a clean round-bottom flask with stirring,and the solid obtained in the previous step was added. The reaction masswas heated to 40-43° C. and stirred at this temperature for 30 min. Thereaction mass was then cooled to 25-30° C. over a period of 30 min., andthen further cooled to 3-5° C. over a period of 2 h, followed bystirring at this temperature for 14 h. Ethanol (3.7 L) was charged tothe reaction mass with stirring, while maintaining the temperature at0-5° C., and the reaction mass was then stirred at this temperature for1 h. The material was then filtered and washed with ethanol (1.47 L),and vacuum dried for 30 min. The material was dried in a vacuum traydryer at 37-40° C. for 24 h under nitrogen atmosphere. The material wasput in clean double LDPE bags under nitrogen atmosphere and stored in aclean HDPE drum. Yield 1.56 kg.

Crystal modification I has an XRPD pattern, obtained withCuKα1-radiation, with characteristic peaks at ° 2θ positions: 3.1±0.2,4.4±0.2, 4.9±0.2, 5.2±0.2, 6.0±0.2, 7.4±0.2, 7.6±0.2, 7.8±0.2, 8.2±0.2,10.0±0.2, 10.5±0.2, 11.3±0.2, 12.4±0.2, 13.3±0.2, 13.5±0.2, 14.6±0.2,14.9±0.2, 16.0±0.2, 16.6±0.2, 16.9±0.2, 17.2±0.2, 17.7±0.2, 18.0±0.2,18.3±0.2, 18.8±0.2, 19.2±0.2, 19.4±0.2, 20.1±0.2, 20.4±0.2, 20.7±0.2,20.9±0.2, 21.1±0.2, 21.4±0.2, 21.8±0.2, 22.0±0.2, 22.3±0.2, 22.9±0.2,23.4±0.2, 24.0±0.2, 24.5±0.2, 24.8±0.2, 26.4±0.2, 27.1±0.2 and 27.8±0.2.The X-ray powder diffractogram is shown in FIG. 4.

Example 2 Preparation of Crystal Modification IV Via EtOH-1

Elobixibat crystal modification I (60 mg) was added to ethanol (1.0 mL)and to a mixture of ethanol and water (0.25+0.75 mL) at 21° C., so as toproduce slurries. A stirring bar was then added to each vessel and thevessels were closed. The vessels were left well stirred at 21° C. forone week. The solid residue in each of the experiment vessels wassampled with a Pasteur pipette to a cut Silicon Zero Background Holder,and the samples were analyzed with two consecutive 1-minute XRPD-scans,from 1 to 40° in 20. After this one or more slightly longer (3 minutesand 12 seconds) XRPD analysis were performed until two consecutive andidentical XRPD-diffractograms had been obtained. When the samples hadbeen analyzed in this way, they were left in the open lab atmosphere for1 day. Under these conditions (approximately 21° C. and 30% relativehumidity) and with the small sample size, ethanol molecules evaporatedfrom the crystal and were replaced by water thereby producing crystalmodification IV.

Example 3 Preparation of Crystal Modification IV Via MeOH-1

Approximately 80 mg of elobixibat crystal modification IV was added to aChromacol vessel and then 1.0 mL of methanol and a stirring flea wasadded. The vessel was closed with a crimped cap, stirred for a day at21° C. and was then sampled to a cut Silicon Zero Background Holder(ZBH) and analysed with XRPD repeatedly as the sample dried. Whenvisually dry it was analysed with TGA and was then allowed to absorbmoisture from the ambient lab atmosphere before it was re-analysed withXRPD. The XRPD-data on the wet sample is shown in FIG. 8 and afterTGA-analysis in FIG. 6.

Example 4 Preparation of Crystal Modification IV Via 1-PrOH-1

99.6 mg of elobixibat crystal modification IV was added to a Chromacolvessel and then 1.0 mL of 1-propanol and a stirring flea was added. Thevessel was closed with a crimped cap, stirred for a day at 21° C. andwas then sampled to a cut Silicon Zero Background Holder (ZBH) andanalysed with XRPD repeatedly as the sample dried. When visually dry itwas analysed with TGA and was then allowed to absorb moisture from theambient lab atmosphere before it was re-analysed with XRPD. TheXRPD-data on the wet sample is shown in FIG. 9 and after TGA-analysis isgiven in FIG. 6.

Example 5 Preparation of Crystal Modification IV Via 2-PrOH-1

103.5 mg of elobixibat crystal modification IV was added to a Chromacolvessel and then 1.0 mL of 2-propanol and a stirring flea was added. Thevessel was closed with a crimped cap, stirred for a day at 21° C. andwas then sampled to a cut Silicon Zero Background Holder (ZBH) andanalysed with XRPD repeatedly as the sample dried. When visually dry itwas analysed with TGA and was then allowed to absorb moisture from theambient lab atmosphere before it was re-analysed with XRPD. TheXRPD-data on the wet sample is shown in FIG. 10 and after TGA-analysisis given in FIG. 6.

Example 6 Preparation of Crystal Modification IV

Toluene (145.9 L) and1,1-dioxo-3,3-dibutyl-5-phenyl-7-methylthio-8-(N-{(R)-1′-phenyl-1′-[N′-(t-butoxycarbonylmethyl)carbamoyl]methyl}carbamoylmethoxy)-2,3,4,5-tetrahydro-1,5-benzothiazepine(7.295 kg) were charged to a 250-L GLR with stirring under nitrogenatmosphere, and the reaction mass was cooled to 3±2° C. Trifluoroaceticacid (21.89 L) was added slowly to the above reaction mass at 3±2° C.over a period of 2-3 h. The temperature of the reaction mass was raisedto 25±5° C. and stirring was continued at this temperature for 21 h. Theprogress of the reaction was monitored by HPLC.

The reaction mass was cooled to 3±2° C. and purified water (29.18 L) wasadded at 3±2° C. with stirring over a period of 30-40 min. The reactionmass was then warmed to 25±5° C. and stirred at this temperature for 15min. The mass was allowed to settle for 15 min. and the layers wereseparated. The organic layer was washed with water (3×29.18 L) and thenwith a saturated brine solution (14.59 L). After each washing, the masswas allowed to settle for 15 min before the layer separation. Theorganic layer was filtered through a stainless steel Nutsche filter overa celite bed (3.0 kg of celite in 17.0 L of toluene) and the filtratewas collected. The celite bed was washed with toluene (14.59 L). Thefiltrates were combined and concentrated at a temperature below 40° C.under vacuum (500-600 mmHg) to about 7 to 14 L.

The above mass was cooled to 25±5° C. and n-heptane (72.95 L) was addedover a period of 10-15 min. The mixture was stirred at 25±5° C. for 2 hand then filtered. The filtered solids were washed with n-heptane (14.59L) and suction dried for about 30 min.

The above crude compound was dried in a vacuum tray dryer at 38±2° C.(500-600 mm Hg) for 10-12 h. Crude wt: 6.65 kg. Purity by HPLC: 98.5%.

Absolute ethanol (29.18 L) was charged into a 250 L stainless steelreactor and heated to 43±2° C. The crude product from the previous step(6.65 kg) was added to the pre-heated ethanol and stirred at 43±3° C.for 15 min. The resulting solution was then cooled to 25±5° C. andstirred at this temperature for 1 h. During this time, the solutionturned turbid.

The mass was seeded with crystal modification IV (2.0 g). The mass wasthen cooled to 3±2° C. over a period of 2 h, and stirred at thistemperature for 10 h. The precipitated solids were filtered and thesolids were washed with chilled ethanol (1×3.65 L). The material wassuction dried for 30 min. The material was then dried in a vacuum traydrier at 25±5° C. (500-600 mmHg) for 24 h and then at 63±2° C. (˜600mmHg) for ˜50 h. The dried product was stored in a HDPE container. Yield5.31 kg.

The crystals absorbed water from the air. A water content of 2.70% wasmeasured. The crystals were analyzed by XRPD and the results are shownin FIG. 1.

Example 7 Thermal Gravimetric Analysis of Crystal Modification IV

A sample of crystal modification IV was analyzed with XRPD and the watercontent was checked with TGA. The weight loss for crystal modificationIV was initially slow, but accelerated at about 50° C. and was finalizedat about 80° C. A weight loss of 2.7% w/w was observed.

The experiment could be repeated several times using the same sample,with rather similar results. Although water had been evaporated from thesample during the TGA analysis, the X-ray powder diffractograms takenbefore and after TGA analysis were similar (see FIG. 5). This indicatesthat the absorption of water takes place very rapidly. Furthermore, theexperiment shows that the crystal modification is very stable, as thecrystal shape is maintained upon evaporation and re-absorption of water.

Example 8 Thermal Gravimetric Analysis of Crystal Modification I

A sample of crystal modification I was analyzed with XRPD and the watercontent was checked with TGA. The weight loss occurred immediately atthe onset of the analysis and was finalized at 50-60° C., indicatingthat the water in this compound is more loosely bound than in crystalmodification IV. A weight loss of 0.99% w/w was observed.

Example 9 DSC Analysis of Crystal Modification IV

Crystal modification IV exhibited an endothermic event in thetemperature range 45 to 90° C. (onset 56° C.) with a peak at 78° C.,with an enthalpy of 66.4 J/g. This event is due to the evaporation ofwater and corresponds to a water amount of about 2.9% w/w.

A melting peak was observed in the temperature range 95 to 125° C.(onset 103° C.) with a peak at 110° C.

Example 10 Cryo-DSC Analysis of Crystal Modification I

Crystal modification I exhibited an endothermic event in the temperaturerange 15 to 85° C. (onset 23° C.) with a peak at 56° C., with anenthalpy of 23.2 J/g. This event is due to the evaporation of water andcorresponds to a water amount of about 1.03% w/w.

A melting peak was observed in the temperature range 110 to 145° C.(onset 122° C.) with a peak at 131° C.

Example 11 Dynamic Vapor Sorption Analysis of Crystal Modification IV

A sample of crystal modification IV was weighed into the quartz scalepan of a Scientific Instruments Dynamic Vapor Sorption instrument. Thesample was released of static electricity by moving a radioactiveisotope over it and was then put into the instrument. The sample wasdried by flushing dry nitrogen gas until the weight was constant andthen two consecutive sorption-desorption cycles were run. Crystalmodification IV absorbs approximately 2.45% water between 0 and 10% RH,and an additional 0.36 to 0.37% water between 10 and 60% RH. Theresulting graph is shown in FIG. 11.

In FIG. 12, a graph of the water uptake as a function of % RH is shown.The sample used in FIG. 12A was obtained from material produced on labscale, whereas the sample used in FIG. 12B was obtained from GMPmaterial produced on pilot plant scale.

Example 12 Dynamic Vapor Sorption Analysis of Crystal Modification I

A sample of crystal modification I was weighed into the quarts scale panof a Scientific Instruments Dynamic Vapor Sorption instrument. Thesample was released of static electricity by moving a radioactiveisotope over it and was then put into the instrument. The sample wasdried by flushing dry nitrogen gas until the weight was constant andthen two consecutive sorption-desorption cycles were run. Crystalmodification I absorbs approximately 0.66% water between 0 and 10% RH,and an additional 0.65 to 0.69% water between 10 and 60% RH. Theresulting graph is shown in FIG. 13. In FIG. 14 a graph of the wateruptake as a function of % RH is shown.

Example 13 Stability Test of Crystal Modification IV

A batch of crystal modification IV was stored in a closed glass vial andkept at 20° C. and between 20 and 60% RH for 17 months. XRPD dataindicated that the crystalline form was unchanged after 17 months.

Example 14 Micrograph of Crystal Modification IV

With a small spatula a small amount of crystal modification IV was puton an objective slide. A drop of Miglyol was added and the solid andliquid were thoroughly mixed with a needle, thus generating a slurry. Acover slip was put on top of the slurry and gently pushed down. Theobjective slide was then put on the rotating table of a Nikon Optiphot-2polarized light microscope. The view of the slurry was well focused andthe light was then adjusted to Köhler illumination. Then the secondpolarizer (the analyzer) was inserted perpendicular to the first one(the polarizer) so that the two polarizers were perfectly crossed. Theanalyzer was then slightly rotated so as to make the two polarizersslightly uncrossed. The specimen was carefully focused and thenphotographed through a 10 times objective giving FIG. 15.

Example 15 Micrograph of Crystal Modification I

Following the procedure outlined in Example 14 but using crystalmodification I instead, the micrograph shown in FIG. 16 was obtained.

Example 16 Thermal Gravimetric Analysis of Crystal Modification EtOH-1

The solvent content of a sample of EtOH-1 was analyzed with TGA. Aweight loss of approximately 6% w/w was observed, indicating that thiscrystal modification contains one mole of ethanol.

Example 17 High-Resolution X-Ray Powder Diffractogram of Elobixibat andTablets Comprising Crystal Modification I or IV Measurement Method:

X-ray powder diffraction in a high brilliance radiation facility‘SPring-8 26B1’Detector: R-AXIS V imaging plate detector (Manufacturer: RIGAKU)Radiation wavelength: 1.0000 ÅBeam size: 100 μm×100 μmDistance between the sample and the detector: 420 mmSample for measurement: enclosed in a glass capillaryVibrating angle: 80.0°Exposure time: 80 secondsMeasurement range: 3-15° (20)Measurement temperature: 20° C.

X-ray powder diffraction measurements by SPring-8 26B1 of crystalmodification I (obtained in Example 1) and crystal modification IV wereperformed. The results are shown in FIG. 17.

Ingredients were mixed in the quantities shown in Table 1. The mixedpowers were formed into tables with tabletting machinery (ManestyBetapress) under the condition (Weight: 3.15-3.25 g; Height: 3.85 mm) toobtain tablets comprising crystal modification I, tablets comprisingcrystal modification IV and placebo tablets, respectively.

TABLE 1 Amount/unit (mg) Tablets Tablets Ingredients (cr. mod. I) (cr.mod. IV) Placebo Elobixibat (cr. mod. I) 15 — — Elobixibat (cr. mod. IV)— 15 — Microcrystalline cellulose 170.42 170.42 179.42 Mannitol 113.62113.62 119.62 Hypromellose 5 cP 8.00 8.00 8.00 Croscarmellose sodium8.00 8.00 8.00 Silica colloidal anhydrous 1.76 1.76 1.76 Magnesiumstearate 3.20 3.20 3.20 Opadry II 16.0 16.0 16.0

Tablets comprising crystal modification I were ground to perform X-raypowder diffraction measurement with SPring-8 26B1. In order to identifythe diffraction peaks additives other than crystal modification I, X-raypowder diffraction measurement of the placebo tablets was performed withSPring-8 26B1 in the same manner. The characteristic diffraction peaksof tablets comprising crystal modification I were found (FIG. 18).

The tablets were stored under the conditions of 40° C., 75% relativehumidity for 8 weeks. Then, X-ray powder diffraction measurement of thestored tablets was performed with SPring-8 26B1 (FIG. 19). No changeswere observed in the peaks of the X-ray powder diffractogram, and thecharacteristic diffraction peaks of the tablets (crystal modification I)were found.

X-ray powder diffraction measurement of crystal modification IV wasperformed with SPring-8 26B1 in a same manner as above. Thecharacteristic diffraction peaks tablets comprising crystal modificationIV were found (FIG. 20).

The tablets were stored under the conditions of 40° C., 75% relativehumidity for 8 weeks, but no changes were observed in the peaks of theX-ray powder diffractogram; the characteristic diffraction peaks oftablets (crystal modification IV) were found (FIG. 21).

The above results demonstrate that crystal modification IV can existstably in tablets.

1. A monohydrate of elobixibat.
 2. The stoichiometric monohydrateaccording to claim 1, wherein the monohydrate is stable for at least oneyear.
 3. The stoichiometric monohydrate according to claim 2, whereinthe monohydrate is stable for at least three years.
 4. (canceled)
 5. Acrystalline monohydrate of elobixibat, wherein the crystalline form isprepared by forming an elobixibat monoalcoholate, substantiallyconverting the monoalcoholate to an ansolvate, and exposing theansolvate to water vapor.
 6. The crystalline elobixibat according toclaim 5, where the monoalcoholate is a methanolate.
 7. The crystallineelobixibat according to claim 5, where the monoalcoholate is anethanolate.
 8. The crystalline elobixibat according to claim 5, wherethe monoalcoholate is a 1-propanolate.
 9. The crystalline elobixibataccording to claim 5, where the monoalcoholate is a 2-propanolate. 10.Crystal modification IV of elobixibat, having an XRPD pattern, obtainedwith CuKα1-radiation, with peaks at ° 2θ positions 6.3±0.2 and 19.4±0.2.11. The crystal modification according to claim 10, having an XRPDpattern, obtained with CuKα1-radiation, with peaks at ° 2θ positions6.3±0.2 and 19.4±0.2 and one or more of the characteristic peaks:10.2±0.2, 10.5±0.2, 9.4±0.2, 9.5±0.2, 12.5±0.2, 14.6±0.2, 15.6±0.2, and23.3±0.2.
 12. Crystal modification IV of elobixibat according to claim10, having an XRPD pattern, obtained with CuKα1-radiation, as shown inFIG.
 1. 13.-20. (canceled)
 21. Crystal modification I of elobixibat,having an XRPD pattern, obtained with CuKα1-radiation, with peaks at °2θ positions 5.2±0.2 and 10.0±0.2.
 22. Crystal modification I ofelobixibat according to claim 21, having an XRPD pattern, obtained withCuKα1-radiation, as shown in FIG.
 4. 23.-31. (canceled)
 32. Thestoichiometric monohydrate according to claim 1, wherein the monohydrateis crystalline.
 33. The crystalline elobixibat according to claim 5,where the monoalcoholate is crystalline.
 34. The crystalline elobixibataccording to claim 5, where the ansolvate is partly crystalline.
 35. Thecrystal modification according to claim 21, having an XRPD pattern,obtained with CuKα1-radiation, with characteristic peaks at ° 2θpositions: 5.2±0.2 and 10.0±0.2 and one or more of the characteristicpeaks: 4.9±0.2, 6.0±0.2, 7.6±0.2, 10.5±0.2, 11.3±0.2, 18.8±0.2,20.4±0.2, and 22.9±0.2.